There are a number of reasons why it may be desirable to occlude a body cavity. For example, the site of a stroke or other vascular accident can be treated by placing an occlusion device proximal of the site to block the flow of blood to the site, thereby alleviating leakage at the site. An aneurysm can be treated by the introduction of an occlusion device through the neck of the aneurysm. Tumors can be treated by occluding the flow of blood to a target site of interest.
A number of different devices may be used to occlude a body cavity, such as a blood vessel. One example of such an occlusion device is an embolization coil. Embolization coils are permanent and promote blood clots or tissue growth over a period of time, thereby occluding the body cavity. However, while the blood clots or the tissue grow, blood may continue to flow past the coil and through the body cavity. It may take a significant period of time for sufficient tissue to grow to fully occlude the body cavity. This leaves a patient open to a risk of injury from the condition which requires the body cavity be occluded.
Other occlusion devices include a coil having fibers, threads or strands attached to the coil. Such occlusion devices act to block the flow of blood through a vessel by the formation of an embolus in the vessel. However, while these occlusion devices can provide effective occlusion, they too suffer from the disadvantage that blood flow continues until the embolus has been formed, thus requiring additional time before effective occlusion is obtained.
Plug-style occlusion devices have also been developed. While these devices are intended to provide a physical barrier to blood flow, and thereby stop blood flow more quickly, known devices are generally bulky and often require thrombosis to obtain reliable occlusion.